US4495298A
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Thallium-containing optical glass
Assignee: Nippon Sheet Glass Co Ltd
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Filing: 1982-05-11
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Granted: 1985-01-22
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Expires: 2002-05-11
Abstract
Abstract A thallium-containing optical glass composition which comprises the following oxides in the indicated proportions in mole %: SiO 2 35-80, Tl 2 O 1-30, Tl 2 O+R 2 O (R being an alkali metal) 1-35, ZnO 0-35, GeO 2 0-30, BaO 0-25, TiO 2 0-20, MgO 0-20, B 2 O 3 0-less than 10, ZrO 2 0-2, Al 2 O 3 0-8, SnO 0-5, CaO 0-10, SrO 0-10, PbO 0-10, La 2 O 3 0-5, Bi 2 O 3 0-8, and Ta 2 O 5 0-2, and satisfies the following relations: 5≦ZnO+GeO.sub.2 +BaO+TiO.sub.2 +MgO+B.sub.2 O.sub.3 ≦40, 0.1≦ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO≦8, and 0≦CaO+SrO+PbO+La 2 O 3 +Bi 2 O 3 +Ta 2 O 5 ≦10.
Inventors
- 👤 Takasi Yamagishi
- 👤 Yukio Noguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:35
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/04; C03C13/045; C03C13/046; C03C3/00; C03C3/04; C03C3/062; C03C3/064; C03C3/066; C03C3/07; C03C3/076; C03C3/089; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
A lens having a refractive index gradient, made of a thallium-containing optical glass composition which consists essentially of the following oxides in the indicated proportions in mole % ______________________________________
SiO.sub.2 35-80
Tl.sub.2 O 1-30
Tl.sub.2 O + R.sub.2 O
1-35
(R being an alkali metal)
ZnO 0-35
GeO.sub.2 0-30
BaO 0-25
TiO.sub.2 0-20
MgO 0-20
B.sub.2 O.sub.3 0-8
ZrO.sub.2 0-2
Al.sub.2 O.sub.3 0-8
SnO 0-5
CaO 0-10
SrO 0-10
PbO 0-10
La.sub.2 O.sub.3 0-5
Bi.sub.2 O.sub.3 0-8
Ta.sub.2 O.sub.5 0-2
______________________________________ and satisfies the following relations 5≦ZnO+GeO.sub.2 +BaO+TiO.sub.2 +MgO+B.sub.2 O.sub.3 ≦40, 0.1≦ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO≦8, 0≦CaO+SrO+PbO+La.sub.2 O.sub.3 +Bi.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 ≦10, and 0≦Li.sub.2 O≦7, said lens having an aperture angle (θc) on its optical axis of not less than 19 degrees.
Claim 2
Dependent Claim
122 words
A lens having a refractive index gradient, made of a thallium-containing optical glass composition which consists essentially of the following oxides in the indicated proportions in mole % ______________________________________
SiO.sub.2 35-80
Tl.sub.2 O 1-30
Tl.sub.2 O + R.sub.2 O
1-35
(R being an alkali metal)
ZnO 0-35
GeO.sub.2 0-30
BaO 0-25
TiO.sub.2 0-20
MgO 0-20
B.sub.2 O.sub.3 0-8
ZrO.sub.2 0-2
Al.sub.2 O.sub.3 0-8
SnO 0-5
CaO 0-10
SrO 0-10
PbO 0-10
La.sub.2 O.sub.3 0-5
Bi.sub.2 O.sub.3 0-8
Ta.sub.2 O.sub.5 0-2
______________________________________ and satisfies the following relations 5≦ZnO+GeO.sub.2 +BaO+TiO.sub.2 +MgO+B.sub.2 O.sub.3 ≦40, 0.1≦ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO≦8, 0≦CaO+SrO+PbO+La.sub.2 O.sub.3 +Bi.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 ≦10, and 0≦Li.sub.2 O≦7, said lens having an aperture angle (θc) on its optical axis of not less than 19 degrees.
Claim 3
Dependent Claim
19 words
The lens of claim 1 wherein the glass composition comprises 2 to 20 mole % of Tl 2 O.
Claim 4
Dependent Claim
29 words
The lens of claim 1 wherein, in the glass composition, R 2 O is K 2 O and is included in a proportion of 2 to 34 mole %.
Claim 5
Dependent Claim
31 words
The lens of claim 1 wherein, in the glass composition, the total proportion of Tl 2 O and R 2 O is in the range of 5 to 25 mole %.
Claim 6
Dependent Claim
97 words
The lens of claim 1 wherein the glass composition consists essentially of the following oxides in the indicated proportions in mole % ______________________________________
SiO.sub.2 45-70
Tl.sub.2 O 2-20
Tl.sub.2 O + R.sub.2 O
5-25
ZnO 5-25
GeO.sub.2 3-15
BaO 5-10
TiO.sub.2 3-15
MgO 5-15
B.sub.2 O.sub.3
0-5
ZrO.sub.2 not more than 1
Al.sub.2 O.sub.3
not more than 5
SnO not more than 3
CaO not more than 5
SrO not more than 5
PbO not more than 5
La.sub.2 O.sub.3
not more than 4
Bi.sub.2 O.sub.3
not more than 7
Ta.sub.2 O.sub.5
not more than 1.5.
______________________________________
Claim 7
Dependent Claim
37 words
The lens of any one of claims 1 to 5 wherein the glass composition satisfies the following relations 10≦ZnO+GeO.sub.2 +BaO+TiO.sub.2 +MgO+B.sub.2 O.sub.3 ≦30, 0.5≦ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO≦5, 0≦CaO+SrO+PbO+La.sub.2 O.sub.3 +Bi.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 ≦5, and 0≦Li.sub.2 O≦7.
Claim 8
Dependent Claim
19 words
The lens of any one of claims 1 to 5 wherein the glass composition further comprises a clarifying agent.
Claim 9
Dependent Claim
22 words
The lens of claim 7 wherein the clarifying agent is selected from As 2 O 3 and Sb 2 O 3 .
Claim 10
Dependent Claim
23 words
The lens of claim 7 wherein the proportion of the clarifying agent in the glass composition is not more than 0.5 mole %.
Claim 11
Dependent Claim
24 words
The lens of claim 1 wherein, in the glass composition, the amount of B 2 O 3 is not more than 5 mole %.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |